Monthly and daily 5km gridded Potential Evapotranspiration (PET) data for the UK. PET was derived using temperature-based equation from McGuinness-Bordne calibrated for the UK (calibration period: 1961-1990). The units are mm/day for daily PET and mm/month for monthly PET. The dataset covers the period from 1891-2015.

For both subsets (daily and monthly), a set of performance metrics were calculated, which are provided together with the PET grids. The list of metrics provided is: Mean Absolute Percent Error (MAPE), Nash-Sutcliffe Efficiency (NSE), Kling-Gupta Efficiency (KGE), Correlation Coefficient, Variability Ratio (VR), Bias Ratio and monthly MAPE.

Provenance & quality

Potential Evapotranspiration (PET) for this dataset was derived using temperature-based equation from McGuinness-Bordne (Oudin et al., 2005, doi: 10.1016/j.jhydrol.2004.08.026). The temperature used to derive the PET grids are the 5km mean temperature grids provided by the Met Office, which were derived using the same methodology as UKCP09 dataset (Perry and Hollis, 2005, doi:10.1002/joc.1161). The monthly temperature data was then disaggregated to daily temperature time series using pchip (piecewise cubic hermite interpolating polynomial) method. McGuinness-Bordne temperature-based Potential Evapotranspiration (PET) equation was calibrated for the UK (calibration period: 1961-1990). This calibrated version was then applied to produce the gridded daily PET. Monthly totals were derived from the daily PET grids to produce monthly PET grids. A set of performance metrics (Mean Absolute Percent Error (MAPE), Nash-Sutcliffe Efficiency (NSE), Kling-Gupta Efficiency (KGE), Correlation Coefficient, Variability Ratio (VR), Bias Ratio and monthly MAPE) were calculate to estimate the goodness-of-fit of the McGuinness-Bordne equation. These metrics are provided as grids as part of the dataset, and can be used as a measure of the spatial variability of the quality of the data.